2.4.2 Parabolic Plane Flights
Microgravity times of several minutes are provided by very special parabolic flight
maneuvers with airplanes. The term parabolic flight describes a flight maneuver that
enables an aircraft, rocket or spacecraft to follow a free-fall ballistic Keplerian
trajectory (Ruyters and Friedrich 2006b; Pletser et al. 2015). Parabolic flights of
aircrafts have become a working horse for training astronauts, hardware testing
and preparation for ISS experiments as well as for stand-alone biomedical and
psychological experiments on human subjects and a broad variety of biological
experiments.
Since 2015, the Airbus A310 ZERO-G, which replaced the old A300 Zero-G
aircraft, is the largest aircraft for European microgravity research (Pletser et al.
2015). It is operated by Novespace, a subsidiary of the French National Space
Center (CNES), with the European Space Agency ESA and DLR, the German
Space Administration, as frequent customers. Usually, a parabolic flight campaign
consists of 31 parabolas flown at each of the three consecutive flight days. In total,
93 microgravity (μg) phases of approximately 22 s add up to 10 min of μg with a
residual acceleration of about 10
À2 g. The parabolic flight maneuvers can be flown in
such a way that partial g-levels in the range of lunar (0.16 g) and Martian (0.38 g)
gravity are achieved for approx. 22 s (Pletser et al. 2012). Of great advantage for
scientists is the fact that the investigator can bring basically his own familiar—even
bigger—lab equipment on board and can perform the experiment himself during the
flight, thus, being able to monitor and operate his experiment, change experimental
parameters or the experimental set-up during the flight. A major disadvantage might
be the flight profile consisting of alternating phases of hypergravity phases of up to
1.8 g, microgravity and 1 g acceleration in between the parabolic flight phases. A
careful assessment of the results and proper control experiments are necessary to
distinguish clearly between microgravity-induced effects, hypergravity effects and
the effects of vibrations. Nevertheless, these microgravity periods are sufficient to
address numerous questions in the area of gravitational biology ranging from the
impact of microgravity on the cellular level, impacts on physiological parameters
and the behavior of organisms up to biomedical and neurobiological studies on
human subjects in microgravity.
2.4.3 Sounding Rockets and Suborbital Platforms
Microgravity in the range of minutes is provided by parabolic flights of rockets like
MASER, TEXUS and MAXUS (Ruyters and Friedrich 2006a; Seibert and Battrick
2006). Today, sounding rockets are frequently used in microgravity research all over
the world. In Germany, the TEXUS Sounding Rocket Programme (Technologische
EXperimente Unter Schwerelosigkeit) started 1977 and 56 TEXUS rockets have
2.4 From Drop Tower to ISS—Biology in Free Fall
21
Microgravity times of several minutes are provided by very special parabolic flight
maneuvers with airplanes. The term parabolic flight describes a flight maneuver that
enables an aircraft, rocket or spacecraft to follow a free-fall ballistic Keplerian
trajectory (Ruyters and Friedrich 2006b; Pletser et al. 2015). Parabolic flights of
aircrafts have become a working horse for training astronauts, hardware testing
and preparation for ISS experiments as well as for stand-alone biomedical and
psychological experiments on human subjects and a broad variety of biological
experiments.
Since 2015, the Airbus A310 ZERO-G, which replaced the old A300 Zero-G
aircraft, is the largest aircraft for European microgravity research (Pletser et al.
2015). It is operated by Novespace, a subsidiary of the French National Space
Center (CNES), with the European Space Agency ESA and DLR, the German
Space Administration, as frequent customers. Usually, a parabolic flight campaign
consists of 31 parabolas flown at each of the three consecutive flight days. In total,
93 microgravity (μg) phases of approximately 22 s add up to 10 min of μg with a
residual acceleration of about 10
À2 g. The parabolic flight maneuvers can be flown in
such a way that partial g-levels in the range of lunar (0.16 g) and Martian (0.38 g)
gravity are achieved for approx. 22 s (Pletser et al. 2012). Of great advantage for
scientists is the fact that the investigator can bring basically his own familiar—even
bigger—lab equipment on board and can perform the experiment himself during the
flight, thus, being able to monitor and operate his experiment, change experimental
parameters or the experimental set-up during the flight. A major disadvantage might
be the flight profile consisting of alternating phases of hypergravity phases of up to
1.8 g, microgravity and 1 g acceleration in between the parabolic flight phases. A
careful assessment of the results and proper control experiments are necessary to
distinguish clearly between microgravity-induced effects, hypergravity effects and
the effects of vibrations. Nevertheless, these microgravity periods are sufficient to
address numerous questions in the area of gravitational biology ranging from the
impact of microgravity on the cellular level, impacts on physiological parameters
and the behavior of organisms up to biomedical and neurobiological studies on
human subjects in microgravity.
2.4.3 Sounding Rockets and Suborbital Platforms
Microgravity in the range of minutes is provided by parabolic flights of rockets like
MASER, TEXUS and MAXUS (Ruyters and Friedrich 2006a; Seibert and Battrick
2006). Today, sounding rockets are frequently used in microgravity research all over
the world. In Germany, the TEXUS Sounding Rocket Programme (Technologische
EXperimente Unter Schwerelosigkeit) started 1977 and 56 TEXUS rockets have
2.4 From Drop Tower to ISS—Biology in Free Fall
21